A process that is considered to be in control measures the weight of a certain product in ounces. Below are the last 8 samples taken.

	Samples
	1	2	3	4	5	6	7	8
	10	9	13	10	12	10	12	12
	9	9	11	11	13	10	11	12
	10	10	10	11	10	11	10	8
	11	11	10	11	11	12	12	10
	12	10	10	12	10	11	12	8
	11	13	12	10	11	12	11	10
Mean	10.5	10.3	11.0	10.8	11.2	11.0	11.3	10.0

1. Determine control limits for the relevant control chart(s) for z=3.
2. Is the process in control? Why?
3. The operations manager responsible for the quality of this process changes the sample size without altering the control limits calculated in (a). What is the most likely impact of this change on the outcome of SPC?
4. Which control chart(s) might not be useful for improving the quality of education at university? Why?
5. Does the analysis performed in (a) and (b) represent the six sigma approach? Why?